Nanomaterials provide many unique properties for chemical processes. High surface area nanostructured materials provide high sorption capacities with adjustable surface chemistries that can provide controlled selectivity and chemical reactivity. The highly selective nanoengineered sorbents have shown excellent capability in capturing variety of analytes of interest. These include the following: heavy metals and precious metals from aqueous phase; gasses such as carbon-dioxide (CO2); and volatiles and semivolatiles such as explosives molecules from the vapor phase. For many chemical applications the small/fine powder form of most nanostructured materials make them impractical for utilization, particularly in the field involving catalytic separation processes and/or analytical devices that need mass flow to and from the active material. Fine powders, the form of most nanostructured materials after synthesis, are not a useful form factor for most applications. As used herein, the term form factor refers to the configuration (e.g., design and geometry) of an item or object. Further, the chemical and thermal conditions required to modify and adhere the nanomaterials to supports are often destructive to the support structures, surface chemistry, and nanomaterials. The fine structure and high surface area of the nanomaterials make them physically fragile and likely to breakdown or flake off the support during use. Chemical modification of the surface of nanomaterials (i.e. salinization, solution or evaporative deposition) requires immersion in solvents and chemicals which can harm devices. As used herein, the term device encompasses a manufactured article such as, but not limited to, a sensor device (e.g., biosensor) and a semiconductor device (e.g., integrated circuit). Integrating specific nanomaterials with specific surface chemistries is very useful for sensing, separation and other chemical applications but there are clearly significant challenges to the creation of a useful device.
For chemical collection and processing, currently used pure polymer based sorbent materials often lack capacity, surface area, as well as analyte selectivity. Polymers allow for chemical and form factor modification but lack high surface areas and high densities of chemically active sites—either would result in breakdown of the polymer materials.
Additionally, a need exists for the enhancement of thin film membranes for a range of separation applications. Incorporation of nanostructured materials into polymers offers improved performance of the thin films. The combination of these materials have resulted in enhanced properties, such as increased surface area, selectivity, permeability, hydrophobicity, hydrophilicity, thermal stability, mechanical strength, and anti-biofouling. The means to effectively incorporate the nanomaterials into the thin film membrane structures enables better membrane performance. The usage of the incorporated nanostructured materials into polymers for separation and chemical reaction applications ranges from desalination, water treatment, and catalytic reactions, to gas separation. Increasing the performance of such membranes would improve process efficacy and facilitate reduced energy consumption and physical size for major chemical processing facilities.
For analytical collections, membrane separations, catalysis and other chemical processes, what is needed is a porous composite material and method that immobilizes high surface area nanomaterials, enables access of the surface area to chemical species of interest, and methods that allow the material to be manufactured in useful forms such as thin film coupled to a substrate.